Your friend says that since you can see objects such as grass and flowers, they must be emitting light in the visible light range. Is your friend correct? Why or why not? My friend is not correct. Although objects such as grass and flowers emit light, they emit light that is not visible to humans because it is in the ultraviolet range.

My friend is not correct. The light that you see from objects such as grass and flowers is actually reflected light, not light that they emit themselves.

My friend is correct. In order for our eyes to see an object, the object must be emitting light.

My friend is correct. These objects do emit light. But they emit light that is not visible to humans because it is in the ultraviolet range. This is why you do not see them at night.